Technology has been a part of stock investing for as long as anyone now alive can remember, but it wasn’t always so. From its informal beginnings in 1792, until the year 1844, when the telegraph was invented, the only way for people to know the prices of stocks on the New York Stock Exchange was to actually be there. Failing that, brokers and investors relied on runners, who sprinted from the trading floor with news for those who employed them. The first big technological advance was the introduction of the telegraph (after its invention in 1844), which allowed the...